Two lanostane triterpenoids with α-glucosidase inhibitory activity from the fruiting bodies of Ganoderma weberianum

A new oxygenated lanostane-type triterpenoid, 20S,24S-epoxy-lanosta-7,9(11)-dien-3β,15α,25R,26-tetraol (1), together with three known compounds (2–4) were isolated from the fruiting bodies of Ganoderma weberianum. Extensive NMR spectrometry and HRESIMS analysis, as well as NMR and ECD calculations elucidated the structure of the new compound. 27-nor-3β-hydroxylanosta-7,9(11),23E-trien-25-one (2) showed superior α-glucosidase inhibitory activity with IC50 value of 122.1 μM to that of positive control acarbose (304.6 μM).